Review of fast Monte Carlo codes for dose calculation in treatment planning

An important need in radiation therapy is a fast and accurate treatment planning system. This system using CT data and characteristics of the radiation beam, calculates the dose in all points of the patient’s volume. Two main factors in planning system are “accuracy” and “speed”. According to these factors, various generation of treatment planning systems are developed. This article is the review of Fast Monte Carlo treatment planning systems which are accurate and fast have both factors at the same time. Monte Carlo techniques are based on the transport of each individual particle (e.g. photon or electron) in the tissue. The transport of the particle is done using the physics of interactions of the particles with matter. Other techniques transport the particles as a group. For a typical dose calculation in radiation therapy the code has to transport some few million particles which take few hours Therefore the Monte Carlo techniques are accurate but slow for clinical use. In recent years with development of the “fact” Monte Carlo the system one is able to perform dose calculation in reasonable time for clinical use. The acceptable time for dose calculation is in the range of the one minute. There is currently a growing interest in fast Monte Carlo treatment planning systems and there are many commercial treatment planning systems the perform dose calculation in radiation therapy based on Monte Carlo technique.